/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.shardingsphere.encrypt.rewrite.parameter.rewriter;

import lombok.Setter;
import org.apache.shardingsphere.encrypt.rewrite.aware.DatabaseNameAware;
import org.apache.shardingsphere.encrypt.rewrite.aware.EncryptConditionsAware;
import org.apache.shardingsphere.encrypt.rewrite.aware.EncryptRuleAware;
import org.apache.shardingsphere.encrypt.rewrite.condition.EncryptCondition;
import org.apache.shardingsphere.encrypt.rewrite.condition.impl.EncryptBinaryCondition;
import org.apache.shardingsphere.encrypt.rule.EncryptRule;
import org.apache.shardingsphere.encrypt.rule.EncryptTable;
import org.apache.shardingsphere.encrypt.rule.column.EncryptColumn;
import org.apache.shardingsphere.infra.binder.context.statement.SQLStatementContext;
import org.apache.shardingsphere.infra.binder.context.type.WhereAvailable;
import org.apache.shardingsphere.infra.database.core.type.DatabaseTypeRegistry;
import org.apache.shardingsphere.infra.rewrite.parameter.builder.ParameterBuilder;
import org.apache.shardingsphere.infra.rewrite.parameter.builder.impl.StandardParameterBuilder;
import org.apache.shardingsphere.infra.rewrite.parameter.rewriter.ParameterRewriter;

import java.util.Collection;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Predicate parameter rewriter for encrypt.
 */
@Setter
public final class EncryptPredicateParameterRewriter implements ParameterRewriter, EncryptRuleAware, EncryptConditionsAware, DatabaseNameAware {
    
    private EncryptRule encryptRule;
    
    private Collection<EncryptCondition> encryptConditions;
    
    private String databaseName;
    
    @Override
    public boolean isNeedRewrite(final SQLStatementContext sqlStatementContext) {
        return sqlStatementContext instanceof WhereAvailable && !((WhereAvailable) sqlStatementContext).getWhereSegments().isEmpty();
    }
    
    @Override
    public void rewrite(final ParameterBuilder paramBuilder, final SQLStatementContext sqlStatementContext, final List<Object> params) {
        String schemaName = sqlStatementContext.getTablesContext().getSchemaName().orElseGet(() -> new DatabaseTypeRegistry(sqlStatementContext.getDatabaseType()).getDefaultSchemaName(databaseName));
        for (EncryptCondition each : encryptConditions) {
            encryptParameters(paramBuilder, each.getPositionIndexMap(), getEncryptedValues(schemaName, each, each.getValues(params)));
        }
    }
    
    private List<Object> getEncryptedValues(final String schemaName, final EncryptCondition encryptCondition, final List<Object> originalValues) {
        String tableName = encryptCondition.getTableName();
        String columnName = encryptCondition.getColumnName();
        EncryptTable encryptTable = encryptRule.getEncryptTable(tableName);
        EncryptColumn encryptColumn = encryptTable.getEncryptColumn(columnName);
        if (encryptCondition instanceof EncryptBinaryCondition && "LIKE".equals(((EncryptBinaryCondition) encryptCondition).getOperator()) && encryptColumn.getLikeQuery().isPresent()) {
            return encryptColumn.getLikeQuery().get().encrypt(databaseName, schemaName, tableName, columnName, originalValues);
        }
        return encryptColumn.getAssistedQuery().isPresent()
                ? encryptColumn.getAssistedQuery().get().encrypt(databaseName, schemaName, tableName, columnName, originalValues)
                : encryptColumn.getCipher().encrypt(databaseName, schemaName, tableName, columnName, originalValues);
    }
    
    private void encryptParameters(final ParameterBuilder paramBuilder, final Map<Integer, Integer> positionIndexes, final List<Object> encryptValues) {
        if (!positionIndexes.isEmpty()) {
            for (Entry<Integer, Integer> entry : positionIndexes.entrySet()) {
                ((StandardParameterBuilder) paramBuilder).addReplacedParameters(entry.getValue(), encryptValues.get(entry.getKey()));
            }
        }
    }
}
